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Microwave and Wireless Components Letters, IEEE

Issue 8 • Date Aug. 2007

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Displaying Results 1 - 25 of 27
  • Table of contents

    Publication Year: 2007 , Page(s): C1 - C4
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    Freely Available from IEEE
  • IEEE Microwave and Wireless Components Letters publication information

    Publication Year: 2007 , Page(s): C2
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  • A Recovery Algorithm for Frequency-Domain Layered Finite Element Analysis of Large-Scale High-Frequency Integrated Circuits

    Publication Year: 2007 , Page(s): 553 - 555
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (166 KB) |  | HTML iconHTML  

    A recovery algorithm is proposed for the frequency-domain layered finite element analysis of large-scale high-frequency integrated circuits. Given the solution in one layer, this algorithm can recover the solutions in other layers with single-layer computational complexity. Numerical and experimental results are given to demonstrate its validity. View full abstract»

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  • Rigorous Analysis of Numerical Phase and Group Velocity Bounds in Yee's FDTD Grid

    Publication Year: 2007 , Page(s): 556 - 558
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (104 KB) |  | HTML iconHTML  

    We present a systematic derivation of the extreme values of phase and group velocity in Yee's finite difference time domain (FDTD) lattice with unequal aspect ratios. Using a Lagrange multiplier based approach; we derive necessary conditions that propagation vector components need to satisfy to attain extreme values in phase and group velocity. Knowledge of these extreme values is useful in designing low numerical dispersion FDTD schemes and also seeding numerical inversion routines of FDTD dispersion relations. View full abstract»

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  • Dielectric Interface Conditions for General Fourth-Order Finite Difference

    Publication Year: 2007 , Page(s): 559 - 561
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (313 KB) |  | HTML iconHTML  

    In this letter, two dielectric interface conditions, for narrow- and broad-band simulations, are presented for the general fourth-order finite-difference stencil in the space domain. The effectiveness of both conditions is verified by numerical simulations. View full abstract»

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  • A Passivity Enforcement Scheme for Delay-Based Transmission Line Macromodels

    Publication Year: 2007 , Page(s): 562 - 564
    Cited by:  Papers (11)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (126 KB) |  | HTML iconHTML  

    This letter presents an algorithm for the enforcement of passivity in transmission-line macromodels based on the generalized method of characteristics. The algorithm is based on first-order perturbations of the solutions to a frequency-dependent eigenvalue problem. The theoretical formulation provides an extension of techniques that were available only for lumped models to the more general class of delay-based models. View full abstract»

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  • Cavities Involving Metamaterials With an Uncountable Set of Resonant Frequencies

    Publication Year: 2007 , Page(s): 565 - 567
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (101 KB) |  | HTML iconHTML  

    In this letter, it is shown that cavity resonators involving lossless and nondispersive (in a frequency band) double negative metamaterials can behave in a completely different way with respect to the cavities involving only traditional nondispersive double positive media. More precisely, it is proven that resonators with only nondispersive media may have an uncountable set of resonant frequencies. As practical consequences, it is outlined that this fact can represent an unsurmountable difficulty for present-day numerical simulators of electromagnetic eigenproblems and a cause of troubles for numerical solvers of electromagnetic driven problems. The presented result should warn users of numerical simulators against the employment of simplified models of metamaterials. View full abstract»

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  • Coaxial Waveguide Based Left-Handed Transmission Line

    Publication Year: 2007 , Page(s): 568 - 570
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    In this letter, a new realization of left-handed transmission line (LHTL) is presented; the proposed structure is realized by periodically loading the coaxial waveguide with gaps in the inner conductor and wires between the inner and outer conductors, the gaps and wires act as series capacitors and shunt inductors. The dispersion characteristic of this new LHTL is analyzed by means of high frequency structure simulator (HFSS) eigenmode simulation and microwave network theory, which exhibits LH behavior over a 60% bandwidth. A backward wave behavior is unambiguously demonstrated from HFSS driven modal simulation. The phase front is observed to be in the opposite direction with respect to the energy one for a finite nine-unit cell prototype. View full abstract»

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  • A High-Q Millimeter-Wave Air-Lifted Cavity Resonator on Lossy Substrates

    Publication Year: 2007 , Page(s): 571 - 573
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (463 KB) |  | HTML iconHTML  

    In this letter, a 3D high-quality-factor millimeter- wave cavity resonator is integrated on the lossy soda-lime glass substrate utilizing surface micromachining technologies. With a height of 300 mum, the air-lifted cavity features a measured Q of at least 219 at 30 GHz, demonstrating an improvement by almost an order of magnitude with respect to respective planar resonators on the same substrate. The 3D cavity is monolithically integrated on the top of the substrate, with its side walls consisting of two rows of metalized pillars, while a weak coupling excitation scheme is used to extract the quality factor. This high performance cavity can be easily integrated with other monolithic integrated circuits and planar mm-wave components in multilayer modules. View full abstract»

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  • Microstrip Open-Loop Resonator With Multispurious Suppression

    Publication Year: 2007 , Page(s): 574 - 576
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (189 KB) |  | HTML iconHTML  

    A compact open-loop resonator with multispurious suppression is proposed. When excited symmetrically, the resonator shows two tunable transmission zeros. By adjusting the open-end gap capacitance, one of the zeros is placed near the passband and the other is tuned to collocate with the leading two degenerated higher order resonances, so that the circuit has a sharp transition as well as a wide upper stopband. The experimental circuit shows the first spurious peak occurs at four times the passband frequency (4fo), and the measurement shows good agreement with the theoretic prediction. View full abstract»

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  • Multichannel Filters Using Chirped Bandgap Structures in Microstrip Technology

    Publication Year: 2007 , Page(s): 577 - 579
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (381 KB) |  | HTML iconHTML  

    We demonstrate two techniques for creating several narrowband transmission channels within the ultra-wide stopband of a chirped electromagnetic bandgap structure in microstrip technology. In contrast to previous demonstrations which inserted defects into single-frequency-tuned bandgap structures using ground-plane etching, we demonstrate the use of local pi phase-shifts (defects) and "Moire"-type superposition in a sinusoidal chirped bandgap structure having a network topology. We demonstrate the design of 4-to-6-channel filters with lower insertion losses (<5 dB) and broader stopbands than previous approaches in microstrip. View full abstract»

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  • A Miniature Dual-Mode Bandpass Filter Using Al2O3 Substrate

    Publication Year: 2007 , Page(s): 580 - 582
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    A dual-mode bandpass filter using the degenerate modes of a modified square ring structure printed on the high-permittivity substrate is proposed. The dual-mode resonator is based on a square ring loaded with a cross-strip. The filter is printed on the Al2O3 substrate with a permittivity of 9.8 and could be easily integrated with radio frequency circuits. Besides its simple structure, the filter shows low insertion loss and small size, owing to the high-permittivity substrate used. The proposed filter shows a size reduction of 44% compared with the case using a simple cross-strip, and it also provides transmission zeros on both sides of the bandwidth. Experimental results are in good agreement with simulated values. View full abstract»

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  • Dual-Band Bandpass Filters Using Stub-Loaded Resonators

    Publication Year: 2007 , Page(s): 583 - 585
    Cited by:  Papers (135)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (179 KB) |  | HTML iconHTML  

    Dual-band bandpass filters using novel stub-loaded resonators (SLRs) are presented in this letter. Characterized by both theoretical analysis and full-wave simulation, the proposed SLR is found to have the advantage that the even-mode resonant frequencies can be flexibly controlled whereas the odd-mode resonant frequencies are fixed. Based on the proposed SLR, a dual-band filter is implemented with three transmission zeros. To further improve the selectivity, a filter with four transmission zeros on either side of both passbands is designed by introducing spur-line. The measured results validate the proposed design. View full abstract»

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  • Quasi-Elliptic Microstrip Low-Pass Filters Using an Interdigital DGS Slot

    Publication Year: 2007 , Page(s): 586 - 588
    Cited by:  Papers (34)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (660 KB) |  | HTML iconHTML  

    This letter introduces a DGS slot with an interdigital shape. The resonant frequency of the slot can be easily controlled by changing the length of the metal fingers, without changing the area taken by the structure. Using this slot, two quasi-elliptic low-pass filters were designed, fabricated and tested. The filters have a cut-off frequency of about 3 GHz. View full abstract»

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  • A Wideband Bandpass Filter With Wide Upper Stopband Using Stepped-Impedance Cascadable 180 ° Hybrid Rings

    Publication Year: 2007 , Page(s): 589 - 591
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (311 KB) |  | HTML iconHTML  

    This letter proposes a wideband bandpass filter by cascading two 3-dB stepped-impedance cascadable 180deg hybrid rings with a pair of stepped-impedance lines. Thanks to the stepped-impedance lines, a broad upper stopband is achieved. The stepped-impedance vertically installed planar (VIP) coupler is used to implement the ideal 180deg phase inverter and crossovers. The experimental results show that this 2-GHz center frequency, fourth order filter has a 10-dB return loss bandwidth of 92.5% and upper stopband rejection levels of better than -20 dB up to 6.8 GHz. This proposed filter achieves wide passband and broad stopband performance simultaneously. View full abstract»

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  • Fully Integrated Broadband CPW Left-Handed Metamaterials Based on GaAs Technology for RF/MMIC Applications

    Publication Year: 2007 , Page(s): 592 - 594
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (283 KB) |  | HTML iconHTML  

    A fully integrated broadband coplanar waveguide left-handed metamaterial medium using GaAs technology for radio frequency/monolithic microwave integrated circuit (RF/MMIC) applications is reported and validated by the full wave simulation and measured results. The unit cell of the fabricated structures has a size of 0.09 mm2. The left handedness of the integrated left-handed structure extends from 2.3 to 17.5 GHz. The compactness and broad left-handed operating bandwidth make the presented left-handed metamaterial be well incorporated with RF/MMIC applications. View full abstract»

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  • A Compact Quadrature Hybrid Based on High-Pass and Low-Pass Lumped Elements

    Publication Year: 2007 , Page(s): 595 - 597
    Cited by:  Papers (9)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (378 KB) |  | HTML iconHTML  

    In this letter, a novel compact quadrature hybrid using low-pass and high-pass lumped elements is proposed. This proposed topology enables significant circuit size reduction in comparison with former approaches applying microstrip branch line or Lange couplers. In addition, it provides wider bandwidth in terms of operational frequency, and provides more convenience to the monolithic microwave integrated circuit layout since it does not have any bulky via holes as compared to those with lumped elements that have been published. In addition, the simulation and measurement of the fabricated hybrid implemented using PHEMT processes are evidently good. With the operational bandwidth ranging from 25 to 30 GHz, the measured results of the return loss are better than 17.6 dB, and the insertion losses of coupled and direct ports are approximately 3.4plusmn0.7 dB, while the relative phase difference is approximately 92.3plusmn1.4deg. The core dimension of the circuit is 0.4 mm times 0.15 mm. View full abstract»

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  • A Compact UWB Three-Way Power Divider

    Publication Year: 2007 , Page(s): 598 - 600
    Cited by:  Papers (23)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (471 KB) |  | HTML iconHTML  

    A three-way power divider with ultra wideband behavior is presented. It has a compact size with an overall dimension of 20 mm times 30 mm. The proposed divider utilizes broadside coupling via multilayer microstrip/slot transitions of elliptical shape. The simulated and measured results show that the proposed device has 4.77 plusmn 1 dB insertion loss, better than 17 dB return loss, and better than 15 dB isolation across the frequency band 3.1 to 10.6 GHz. View full abstract»

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  • Fully Functional Nonlinear Table-Based HBT Model With Explicit Thermal Feedback

    Publication Year: 2007 , Page(s): 601 - 603
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (484 KB) |  | HTML iconHTML  

    A fully functional table-based nonlinear model of the heterojunction bipolar transistor (HBT) is presented which includes explicit thermal feedback. The model uses four table-based nonlinear functions: Ic, Qc, Vbe, and Qb, all defined versus Ib and Vce by using a nonuniform bias grid. Thermal modeling (self-biasing and environment temperature dependence, Ta) is done by linearly mapping the table-based current functions versus Ta coupled with explicit thermal feedback. Four table-based nonlinear coefficients are required to accurately predict the device behavior versus temperature. Excellent results have been obtained under dc, small, and large signal excitations for InGaP/GaAs HBTs in the range 10degC to 110degC. View full abstract»

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  • Simplified Analysis of Resistive Mixers

    Publication Year: 2007 , Page(s): 604 - 606
    Cited by:  Papers (13)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (162 KB) |  | HTML iconHTML  

    This letter gives a simple method for calculation by hand of the conversion efficiency of resistive mixers. The method assumes the same embedding impedances at all mixing frequencies and the mixing element is modeled as a time varying reflection coefficient. This gives simple expressions for the conversion efficiency. It, therefore, allows analytical parameter studies of the impact of the embedding impedance and parameters of the mixing element on the conversion efficiency. The theory is developed in two stages. First at optimum local oscillator power and second for arbitrary power. The theory agrees well with verifying measurements made on a field-effect transistor (FET)-based resistive mixer. View full abstract»

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  • Dual-Band Mixer Using Composite Right/Left-Handed Transmission Lines

    Publication Year: 2007 , Page(s): 607 - 609
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (467 KB) |  | HTML iconHTML  

    The concept of composite right left-handed transmission lines provides for one additional degree of freedom in realizing arbitrary dual-band frequency response devices. In this letter, an arbitrary dual-band operation mixer, based on the classical balanced mixer topology is proposed. The prototype demonstrates the mixer performance for a ratio of 2.5 between the two operation bands (860 MHz and 2,150 MHz). The conversion losses are better than 8.5 dB in both bands. View full abstract»

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  • A Low Phase Noise LC VCO in 65 nm CMOS Process Using Rectangular Switching Technique

    Publication Year: 2007 , Page(s): 610 - 612
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (474 KB) |  | HTML iconHTML  

    A low phase noise and low power LC voltage-controlled oscillator (VCO) has been designed using a 65-nm CMOS process. The phase noise is minimized by switching the differential core using a rectangular shaped voltage waveform, which is formed by a harmonic tuned LC tank assisted by a gm3 boosting circuit. The gm3 boosting circuit effectively maximizes the slope at the zero crossing point and reduces the transition time in which the switching transistor is operated at the triode region. The rectangular switching technique has improved the phase noise of the oscillator by 10 dB. The 450 mum times 540 mum chip consumes 4.34 mW. The proposed VCO has phase noises of -83.3, -110.7, and -131.8 dBc/Hz at 10 KHz, 100 KHz, and 1 MHz offset frequencies, respectively, from the 1.6-GHz carrier frequency. View full abstract»

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  • A Wide Locking Range LC-Tank Injection-Locked Frequency Divider

    Publication Year: 2007 , Page(s): 613 - 615
    Cited by:  Papers (10)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB) |  | HTML iconHTML  

    This letter proposes a wideband injection-locked frequency divider (ILFD) and describes the operation principle of the ILFD. The circuit is made of a differential CMOS LC-tank oscillator and is based on the direct injection topology. The wideband function is obtained by tuning the switch across the tank inductors. The divide-by-two ILFD can provide wide locking range and the measurement results show that at the supply voltage of 1.8 V, the dual-band divider free-running frequencies are from 1.77 to 2.17 GHz for the low-band mode, and from 2.59 to 3.2 GHz for the high-band mode. At the incident power of 0 dBm, the locking range is about 1.7 GHz from the incident frequency 3.31 to 5.01 GHz at low band and 4.06 GHz from 3.94 to 8.0 GHz at high-band mode. The circuit can be used as a single wideband ILFD. View full abstract»

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  • A Compact Wideband CMOS Low-Noise Amplifier Using Shunt Resistive-Feedback and Series Inductive-Peaking Techniques

    Publication Year: 2007 , Page(s): 616 - 618
    Cited by:  Papers (16)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (372 KB) |  | HTML iconHTML  

    A wideband low-noise amplifier (LNA) with shunt resistive-feedback and series inductive-peaking is proposed for wideband input matching, broadband power gain and flat noise figure (NF) response. The proposed wideband LNA is implemented in 0.18-mum CMOS technology. Measured results show that power gain is greater than 10 dB and input return loss is below -10 dB from 2 to 11.5 GHz. The IIP3 is about +3 dBm, and the NF ranges from 3.1 to 4.1 dB over the band of interest. An excellent agreement between the simulated and measured results is found and attributed to less number of passive components needed in this circuit compared with previous designs. Besides, the ratio of figure-of- merit to chip size is as high as 190 (mW-1 /mm2 ) which is the best results among all previous reported CMOS-based wideband LNA. View full abstract»

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  • CMOS Outphasing Class-D Amplifier With Chireix Combiner

    Publication Year: 2007 , Page(s): 619 - 621
    Cited by:  Papers (23)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (383 KB) |  | HTML iconHTML  

    This letter presents a CMOS outphasing class-D power amplifier (PA) with a Chireix combiner. Two voltage-mode class-D amplifiers used in the outphasing system were designed and implemented with a 0.18-mum CMOS process. By applying the Chireix combiner technique, drain efficiency of the outphasing PA for CDMA signals was improved from 38.6% to 48% while output power was increased from 14.5 to 15.4 dBm with an adjacent channel power ratio of -45 dBc. View full abstract»

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Aims & Scope

The IEEE Microwave and Wireless Components Letters (MWCL) publishes three page papers that focus on microwave theory, techniques and applications as they relate to components, devices, circuits, biological effects, and systems involving the generation, modulation, demodulation, control, transmission, and detection of microwave signals.

Full Aims & Scope